Final answer:
Rhodopseudomonas has two major metabolic pathways: anoxygenic photosynthesis as a photoautotroph using organic compounds for electron donation, and anaerobic respiration as a chemoheterotroph with varied final electron acceptors for ATP production.
Step-by-step explanation:
Metabolic Pathways of Rhodopseudomonas
The bacterium Rhodopseudomonas is an anaerobic photoautotroph that can utilize organic compounds as an electron donor through anoxygenic photosynthesis. In this process, the bacterium uses light energy to generate ATP without splitting water to release oxygen, making it anoxygenic. The organic substrates such as succinate and malate are oxidized, channeling electrons through a photosynthetic electron transport chain, resulting in the production of ATP.
In addition to being photoautotrophic, Rhodopseudomonas can also exhibit chemoheterotrophic metabolism. As a chemoheterotroph, it uses organic substrates to produce energy through cellular respiration, but in the absence of oxygen (anaerobic respiration), it can utilize other inorganic or organic molecules as the final electron acceptor to produce ATP. This versatility allows Rhodopseudomonas to survive in a variety of environmental conditions by switching between its metabolic pathways depending on the availability of light, oxygen, and organic or inorganic compounds.